Material handling systems such as those used to process food (inclusive of beverages and dairy products), pharmaceuticals, consumer care products and the like, are cleaned or sterilized on a regular basis in order to avoid contamination. The cleaning or sterilization can be “clean-in place” (CIP) or “steam-in-place” (SIP) methods. Such methods involve, rather than disassembling the system for individual treatment of the components, supplying the cleaning or sterilizing products directly through the system at regular intervals. These CIP and SIP methods can clean or sterilize the system more quickly and efficiently than methods requiring disassembly of the system, thus reducing downtime.
CIP and SIP methods may involve the use of harsh cleaning products (e.g., chemicals) and/or may be performed under relatively extreme environments (e.g., high temperature such as encountered during steam cleaning). These harsh conditions can prematurely wear-out components of the system. In particular, for certain applications, it is desirable to use an open/close valve stem in which the head of the valve stem includes rubber material bonded to a metal head. The rubber is an elastic material that is able to seal against the valve seat.